diff --git a/ChangeLog b/ChangeLog
index 06e3b04..17dedf1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2011-12-20  Niibe Yutaka  <gniibe@fsij.org>
+
+	* src/usb_msc.c (msc_handle_command): SCSI_START_STOP_UNIT command
+	with stop/eject/close means cancelling pinentry.
+
+	* src/pin-dnd.c (pinpad_finish_entry, parse_directory_sector):
+	Implement "cancel".
+	(pinpad_getline): Likewise.
+	(msc_scsi_stop): New.
+
 2011-12-16  Niibe Yutaka  <gniibe@fsij.org>
 
 	* tool/gnuk_put_binary_libusb.py (gnuk_token.cmd_select_openpgp):
diff --git a/NEWS b/NEWS
index bdc1a4c..3b60b77 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,18 @@
 Gnuk NEWS - User visible changes
 
+* Major changes in Gnuk 0.17
+
+  Released 2012-01-XX, by NIIBE Yutaka
+
+** With DnD pinentry, user can cancel pin input
+Now, user can cancel pin input by unmounting device before finishing
+DnD.
+
+** New tool: pinpad-test.py
+The tool pinpad-test.py is PC/SC test tool for pinentry of pinpad with
+OpenPGP card v2.
+
+
 * Major changes in Gnuk 0.16
 
   Released 2011-12-14, by NIIBE Yutaka
diff --git a/src/gnuk.h b/src/gnuk.h
index 6bf3493..e0d72d6 100644
--- a/src/gnuk.h
+++ b/src/gnuk.h
@@ -362,6 +362,7 @@ extern void msc_init (void);
 extern void msc_media_insert_change (int available);
 extern int msc_scsi_write (uint32_t lba, const uint8_t *buf, size_t size);
 extern int msc_scsi_read (uint32_t lba, const uint8_t **sector_p);
+extern void msc_scsi_stop (uint8_t code);
 # endif
 #define PIN_INPUT_CURRENT 1
 #define PIN_INPUT_NEW     2
diff --git a/src/pin-dnd.c b/src/pin-dnd.c
index 3cd1c8d..70d1de9 100644
--- a/src/pin-dnd.c
+++ b/src/pin-dnd.c
@@ -72,13 +72,16 @@ pinpad_getline (int msg_code, systime_t timeout)
       chSysUnlock ();
 
       led_blink (0);
-      if (msg == 1)
+      if (msg != 0)
 	break;
     }
 
   msc_media_insert_change (0);
 
-  return pin_input_len;
+  if (msg == 1)
+    return pin_input_len;
+  else
+    return -1;			/* cancel */
 }
 
 static void pinpad_input (void)
@@ -89,10 +92,13 @@ static void pinpad_input (void)
   chSysUnlock ();
 }
 
-static void pinpad_finish_entry (void)
+static void pinpad_finish_entry (int cancel)
 {
   chSysLock ();
-  pin_thread->p_u.rdymsg = 1;
+  if (cancel)
+    pin_thread->p_u.rdymsg = 2;
+  else
+    pin_thread->p_u.rdymsg = 1;
   chSchReadyI (pin_thread);
   chSysUnlock ();
 }
@@ -328,7 +334,7 @@ static void parse_directory_sector (const uint8_t *p, uint8_t index)
     }
 
   if (index == 0 && num_children == 1)
-    pinpad_finish_entry ();
+    pinpad_finish_entry (0);
   else if (input)
     pinpad_input ();
 }
@@ -357,3 +363,10 @@ msc_scsi_write (uint32_t lba, const uint8_t *buf, size_t size)
       return 0;
     }
 }
+
+void
+msc_scsi_stop (uint8_t code)
+{
+  (void)code;
+  pinpad_finish_entry (1);
+}
diff --git a/src/usb_msc.c b/src/usb_msc.c
index 4262825..77836b9 100644
--- a/src/usb_msc.c
+++ b/src/usb_msc.c
@@ -388,6 +388,17 @@ void msc_handle_command (void)
     buf[11] = (uint8_t)(secsize >> 0);
     msc_send_result (buf, 12);
     return;
+  case SCSI_START_STOP_UNIT:
+    if (CBW.CBWCB[4] == 0x00 /* stop */ 
+	|| CBW.CBWCB[4] == 0x02 /* eject */ || CBW.CBWCB[4] == 0x03 /* close */)
+      {
+	msc_scsi_stop (CBW.CBWCB[4]);
+	set_scsi_sense_data (0x05, 0x24); /* ILLEGAL_REQUEST */
+	contingent_allegiance = 1;
+	keep_contingent_allegiance = 1;
+      }
+    /* CBW.CBWCB[4] == 0x01 *//* start */ 
+    goto success;
   case SCSI_TEST_UNIT_READY:
     if (contingent_allegiance)
       {
@@ -397,9 +408,9 @@ void msc_handle_command (void)
 	return;
       }
     /* fall through */
+  success:
   case SCSI_SYNCHRONIZE_CACHE:
   case SCSI_VERIFY10:
-  case SCSI_START_STOP_UNIT:
   case SCSI_ALLOW_MEDIUM_REMOVAL:
     CSW.bCSWStatus = MSC_CSW_STATUS_PASSED;
     CSW.dCSWDataResidue = CBW.dCBWDataTransferLength;